Optical reflectivity improvement by upgrading metallic glass film quality

Abstract

The effects of atomic-defect and free-volume amounts of metallic glassy film on the optical reflectivity and mechanical properties of the sputtered metallic glass thin films are explored. With a lower Ar working pressure and the proper post-annealing at temperatures slightly lower than the glass-transition temperature Tg, film free volumes and defects would reduce, resulting in better atomic bonding and higher film hardness/modulus, which in turn leads to lower electric resistivity and higher optical reflectivity. Annealing above Tg would induce crystalline structure which would lead to competition with the optical transition of the Drude free electrons and hinder the optical reflectivity in the visible range.